Thread: Underdash plug colors and what they do/go to

EDIT: This basically tells you how to use a highport engine harness to run a highport in your B14.

While searching for the wire color and what each wire does, i noticed that there were a number of threads asking the same question i was wanting to know the answer to. So after a couple months of searching FSM's, pinning ecu's, and using CoalitionSe-L's adapter plug conversions to double check myself....here is a list of the underdash plug's wire colors and what each wire does. there are a couple i do not know what they are for, if you do, please pm me and i will add it to the list.

Color Pin What it does

91 B13:
black/red - no pin- fuel pump relay power wire
white - 46 - one of 2 power supplies for the ecu
blue/black - 10 - rad. fan relay #2
------------------------------------------------
orange/black - 24- check engine light
white/red - 23 - check connector
yellow - 14 - check connector
yellow/red - 41 - i never found what it did
yellow/green - 32 - speedo. signal to cluster
yellow/blue - 11 - a/c relay
blue - 9 - rad. fan relay #1
purple - 34 - start signal
black/yellow - 104 - another fuel pump relay wire
white/green - no pin - not sure
yellow/red - 15 - not sure
blue/black - 2 - tach. signal to cluster

95 B14:
green/orange - 22 - neutral position switch
white/blue - 70 - an ecu power supply
red/yellow - 108 - rear o2 sensor heater
brown/yellow - no pin- i think front o2 sensor
grey/blue -65- check connector
grey - no pin- i think something with o2 sensors
green/black - 64 - check connector
light green/red - 14 - rad. fan #1 relay
orange/blue - 18 - check engine light
green/white - 68 - check connector
white - no pin - joins with grey in the harness..no idea
brown - 25 - power steering switch
black/yellow - 20 - start signal
---------------------------------------
black/red - no pin - fuel pump relay power
light blue/red - 55 - rear defroster
red/blue - 60 - lighting switch
---------------------------------------
light blue/ red - no pin - not sure
black - no pin - ground for something
light green/black - 35 - fan switch
blue/white - 21 - a/c switch
orange - 58 - date link for gst
blue/orange - 3 - tachometer
purple/red - 26 - speedo. signal to cluster
black/pink - 8 - fuel pump relay
green/yellow - 15 - a/c relay

Just a quick question but If using a B13 ECU why does it matter, if using a highport engine, harness, and ECU, it should work in a b14?????? Seems that way anyway. Do the engine and chassis harness not match at all?

nope, engine and chassis harnesses do not match up. that's why i had to figure out what each wire did for it to work.

I have a 95 se-r and a 93 sr20, 93 harness, 93 ecu. What do I need to do what am I changing, if you dont mind helping me out. If I have to buy a 95 engine harness I will, but if I dont have to then great.Thanks

i would love to help you, but i'm pretty sure my pins and colors will only work on 91-92. someone correct me if i am wrong.

pm'd ya . Thanks for any info. I am getting my boosted b14 running this year!!no matter what